Notes:
- 1) The fitting includes the systematic errors.
- 2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
- 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.
Time averaged spectrum fit using the average DRM
Power-law model
Time interval is from -15.044 sec. to 22.652 sec.
Spectral model in power-law:
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Parameters : value lower 90% higher 90%
Photon index: -1.94277 ( -0.136329 0.132806 )
Norm@50keV : 3.00077E-03 ( -0.000261146 0.000257783 )
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#Fit statistic : Chi-Squared = 60.72 using 59 PHA bins.
# Reduced chi-squared = 1.065 for 57 degrees of freedom
# Null hypothesis probability = 3.432357e-01
Photon flux (15-150 keV) in 37.7 sec: 0.438706 ( -0.032441 0.032467 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.04105e-06 ( -8.73268e-08 8.84657e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.044 sec. to 22.652 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.24279 ( -0.594505 0.712118 )
Epeak [keV] : 44.9231 ( -10.2382 27.2602 )
Norm@50keV : 7.60974E-03 ( -0.00410222 0.0121207 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 56.60 using 59 PHA bins.
# Reduced chi-squared = 1.011 for 56 degrees of freedom
# Null hypothesis probability = 4.525474e-01
Photon flux (15-150 keV) in 37.7 sec: 0.425958 ( -0.034159 0.03415 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.04747e-06 ( -1.86987e-07 2.4795e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 9.044 sec. to 10.044 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.11979 ( -0.249563 0.231661 )
Norm@50keV : 9.14607E-03 ( -0.00168764 0.00166096 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 81.10 using 59 PHA bins.
# Reduced chi-squared = 1.423 for 57 degrees of freedom
# Null hypothesis probability = 1.966278e-02
Photon flux (15-150 keV) in 1 sec: 1.45327 ( -0.2059 0.2059 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.51452e-08 ( -1.41269e-08 1.44871e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 9.044 sec. to 10.044 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.0198 ( -1.57053 2.09099 )
Epeak [keV] : 37.0162 ( -5.00493 5.35989 )
Norm@50keV : 0.712559 ( -0.737601 12.4089 )
------------------------------------------------------------
#Fit statistic : Chi-Squared = 66.17 using 59 PHA bins.
# Reduced chi-squared = 1.182 for 56 degrees of freedom
# Null hypothesis probability = 1.658287e-01
Photon flux (15-150 keV) in 1 sec: 1.38705 ( -0.20363 0.20486 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.30887e-08 ( -1.1503e-08 1.25658e-08 ) ergs/cm2
Time-resolved spectra
